Installation structure for drive motor of double suction blower

ABSTRACT

Disclosed herein is an installation structure for a drive motor of a double suction blower which can provide the optimal installation position for the drive motor so as to offer an excellent flow rate of air when the drive motor is installed at any one of both intake ducts of an impeller.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2014-0060051, filed May 20, 2014, which is hereby incorporated by reference in its entirety into this application.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to an installation structure for a drive motor of a double suction blower, and more particularly to an installation structure for a drive motor of a double suction blower which provides the optimal installation position for a drive motor so as to offer an excellent flow rate of air when the drive motor is installed at any one of both intake ducts of an impeller of the double suction blower.

2. Description of the Related Art

Generally, a blower refers to machinery which causes a flow of air, which is used in air cleaning devices, electric fans and the like in the home and is used in air conditioning systems, various intake and exhaust systems in industrial settings.

The blower may be classified into an axial-flow blower, a centrifugal blower and a mixed-flow blower depending on characteristics of air passing an impeller.

The axial-flow blower is configured to cause air flow parallel to a rotating shaft of an impeller Examples thereof include typical domestic electric fans.

The centrifugal blower is configured to cause an intake air flow to be parallel to a rotating shaft but to cause a discharge flow to be perpendicular to the rotating shaft. Examples thereof include typical domestic air cleaning devices.

The centrifugal blower may be classified into a single suction type in which an intake air flow occurs at one side of a rotating shaft and a double suction type in which an intake flow occurs at both sides of the rotating shaft.

The mixed-flow blower is configured to cause an axial intake air flow as well as a radial intake air flow in an impeller, and is used in case where increases in a flow rate and a pressure are required concurrently.

FIG. 1 shows a typical double suction blower 10. The double suction blower comprises an impeller 20 for causing a flow of air and a case 30 for guiding the flow of air drawn in or expelled from the impeller 20.

However, when a drive motor is installed at one side of the double suction blower, the conventional double suction blower causes a pulsating air flow owing to the flow of air drawn in the impeller by a drive motor. Accordingly, there is a need for an installation structure of a drive motor which can minimize the pulsating flow of air caused by position of the drive motor.

The conventional art pertaining to this may include Korean Utility Model Application Publication No. 20-2000-0011426 (Title: Blower having a scroll housing equipped with protrusions, Date of Publication: 5 Jul., 2000)

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an installation structure for a drive motor of a double suction blower which can provide the optimal installation position for the drive motor so as to offer an excellent flow rate of air when the drive motor is installed at any one of both intake ducts of an impeller of the double suction blower.

In order to accomplish the above object, the present invention provides an installation structure for a drive motor of a double suction blower, including: an impeller which is configured to axially draw in air from both sides thereof and to radially expel the drawn air and which is divided into two halves by a partition wall; a case accommodating the impeller, the case including: air intake holes formed at both sides thereof to allow air to be introduced into the impeller at both sides of the impeller and including an outtake guide duct to guide outside the air radially expelled from the impeller; and a drive motor installed at one side of the impeller and coupled to the center of the partition wall to rotate the impeller, wherein the drive motor is disposed at a position in which the drive motor is partially inserted into the impeller from an outer end of the impeller.

The impeller may include outwardly-flared axial intake ducts on both sides thereof to allow air to be drawn in the impeller by the drive motor.

The drive motor may be disposed at a position in which the drive motor is partially inserted into a minimum intake diameter line of the intake ducts.

The drive motor may include a housing configured to have cylindrical shape, and a diameter line of the housing is within a range of 75% to 85% of the minimum intake diameter line of the intake duct.

The drive motor may be disposed in the impeller through the minimum intake diameter line such that an end of the drive motor is positioned at a distance from an outer end of the impeller, the distance being within the range of 20% to 30% of the minimum intake diameter line.

Accordingly, when a drive motor is installed at any one of both intake ducts of an impeller of a double suction blower, the present invention can provide the optimal installation position for the drive motor so as to offer an excellent flow rate of air.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic perspective view showing a conventional double suction blower;

FIG. 2 is a schematic perspective view showing a structure in which a drive motor is coupled to an impeller of a double suction blower according to the present invention;

FIGS. 3A to 3E are schematic views showing five Experimental examples according to present invention, in which drive motors are installed at different positions relative to the impeller of the double suction blower;

FIG. 4 is a comparison graph exhibiting curves of flow rate—static pressure to check the difference between a computational analysis value and an actual measurement value of the present invention

FIG. 5 is a graph showing an inflow efficiency of air according to experimental examples of FIG. 3A to FIG. 3E; and

FIG. 6A and FIG. 6B are schematic views showing the flow of internal air in the impeller in second and third experimental examples of FIG. 3B and FIG. 3C.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings are used throughout the different drawings to designate the same or similar components.

In the following description, redundant descriptions and detailed descriptions of known functions and elements that may unnecessarily make the gist of the present invention obscure will be omitted.

FIG. 2 is a schematic perspective view showing a structure in which a drive motor is coupled to an impeller of a double suction blower according to the present invention.

An installation structure for a drive motor of a double suction blower according to the present invention comprises an impeller 100, a case 200 and a drive motor 300.

The impeller 100 functions to cause air suction at both sides thereof (double suction). More specifically, the impeller 100 is a cylindrical component which draws in air axially inward at both sides thereof and discharges the air radially outward. The impeller 100 includes a multiblade fan 101 through which the drawn-in air is discharged and which is composed of a plurality of blades radially arranged along the circumference of the impeller 100.

The impeller 100 includes a partition wall 102 at the center of the axial length which divides the internal space into two separate independent spaces (upper and lower spaces).

Connected to the center of the partition wall 102 is a rotating shaft 310 of the drive motor 300. Therefore, the impeller 100 rotates by rotative force from the drive motor 300 thus causing air to be axially drawn in and to be radially discharged.

In the case where the drive motor 300 is installed at one side of the impeller 100 which has two separate internal spaces, the present invention aims to provide a geometrical structure which can minimize resistance to air introduced at the one side of the impeller 100 by means of positional change of the drive motor 300.

The impeller 100 is provided axially at both sides thereof with intake ducts 110. The intake ducts 110 are configured to be flared outward.

When the intake duct 110 is flared axially outward as in this embodiment, an amount of air drawn in the impeller 100 can be increased. In particular, when the drive motor 300 is installed at the intake duct 110, air can be smoothly introduced into the impeller 100 thanks to the flared intake duct 110.

In this specification, the minimum and maximum diameters of the intake duct 100, which is configured to be flared axially outward, are referred to as a minimum intake diameter and a maximum intake diameter. As illustrated in FIG. 3A to FIG. 3E, the minimum intake diameter and the maximum intake diameter are indicated by a minimum intake diameter line D1 and a maximum intake diameter line D3.

Although the intake duct 110 may be integrally manufactured with the impeller 100, only the impeller 100 may rotate by the drive motor 300 through an alternative configuration in which a bearing (not shown) is provided between the impeller 100 and the intake duct 110.

As illustrated in FIG. 2, the case 200 is a component which houses the impeller 100. The case 200 is provided at one side thereof with an outtake guide duct 210 functioning to collect and discharge air which is axially drawn in and radially expelled from the impeller 100 as the impeller 100 rotates by the drive motor 300.

Furthermore, the case 200 is provided at both sides thereof with air intake holes 220 which allow air to be supplied into the intake ducts 110 formed at both sides of the impeller 100. Preferably, the air intake holes 220 are fitted on the outer periphery of the intake ducts 110 in a close contact manner.

When only the impeller 100 rotates as described above, the intake ducts 110 are in close contact with the air intake holes. Meanwhile, when the impeller 100 rotates together with the intake ducts 110, bearings (not shown) may be provided between the intake duct 110 and the air intake holes 220.

As mentioned above, the drive motor 300 is installed at one side of the impeller 100. The rotating shaft 310 of the drive motor 300 is coupled to the partition wall 102 so that the impeller can rotate in conjunction with the rotation of the drive motor 300.

The drive motor 300 includes therein a rotator (not shown) and a stator (not shown). The rotator is fixed to the rotating shaft 310 and the rotating shaft 310 is connected to the center of the partition wall 102.

The rotator and the stator are accommodated in a housing which is a case of the drive motor, and the housing may be cylindrically shaped.

Hereinafter, a process of positioning the drive motor 300 in the optimal way when the drive motor 300 of the double suction blower having the configuration mentioned above at the intake duct 110 will be described with reference to FIGS. 4 to 6.

FIG. 4 is a comparison graph exhibiting curves of flow rate—static pressure to check the difference between a computational analysis value and an actual measurement value of the present invention, FIG. 5 is a graph showing an inflow efficiency of air according to experimental examples of FIG. 3A to FIG. 3E, and FIG. 6 is a schematic view showing flow of internal air in the impeller in second and third experimental examples of FIG. 3.

The present invention prepared five experimental examples to achieve the geometrical optimization. The prepared experimental examples include Experimental example (a) in which the drive motor 300 is excluded, Experimental example (b) in which the bottom of the drive motor 300 is positioned at the minimum intake diameter line (D1), Experimental example (c) in which the drive motor 300 is partially inserted into the intake duct 110, Experimental example (d) in which the bottom of the drive motor 300 is positioned at the maximum intake diameter line (D3), and Experimental example (e) in which the drive motor 300 is displaced outward to produce a free space corresponding to the axial length of the drive motor 300.

In FIG. 4, curves of flow rate—static pressure representing performance of a centrifugal blower were compared with each other so as to visibly check the difference between a computational analysis value and an actual measurement value.

Referring to FIG. 4, it was noted that the computational analysis value is exhibited as being too high compared to the actual measurement value. It was believed that the reason is because the effects due to temperature were not considered.

In particular, the significant fact in the comparison between two values is that the actual measurement value varies with a substantial constant gap with respect to the computational analysis value. Accordingly, it was found that the validation of the experimental examples using the methodology of the present invention produces significant data.

Referring to FIG. 5, there are shown results of five Experimental examples (a)-(e). Experimental example (a) in which the intake duct 110 is not provided with the drive motor 300 is believed as being theoretically the most ideal example.

Meanwhile, for Experimental example (e), the drive motor 300 is spaced apart from the intake duct 110 such that there is no resistance to air being drawn in the intake duct 110 during rotation of the drive motor 300. When the drive motor 300 is spaced apart from the intake duct 110 as in Experimental example (e), a size of the double suction blower is unnecessarily increased thus remarkably deteriorating a degree of freedom of design.

In other words, although it is most ideal that the drive motor 300 is installed at a position spaced apart from the intake duct 110 by a certain distance, it is difficult to apply Experimental example (e) to an actual double suction blower because Experimental example (e) is subjected to many restrictions.

Accordingly, Experimental examples (a) and (e) were merely presented so as to allow efficiencies with air flow rates of Experimental examples (a) and (b) to be compared with those of Experimental examples (b)-(d), and cannot be considered as actual models

In five Experimental examples illustrated in FIG. 5, the minimum intake diameter line (D1) is 144 mm, a diameter line (D2) of the drive motor 300 is 116 mm, the maximum intake diameter line (D3) is 161 mm, and an axial length (height) of the drive motor 300 is 70 mm, as illustrated in FIG. 3A to FIG. 3E. In FIG. 3C, (H) represents a distance between the minimum intake diameter line (D1) and the bottom of the drive motor 300.

Furthermore, a width (height) of the impeller 100 excluding the intake ducts 110 is 110 mm. In this context, since the impeller 100 is divided into two halves by the partition wall 102, a width of each of the half impellers has a width of 55 mm.

The comparison of performance between Experimental examples (a)-(e) is represented in FIG. 5. As illustrated in FIG. 5, it was found that Experimental example (c) exhibits the best flow rate efficiency with respect to flow rate because a constant flow rate can be maintained (suppression of counter flow) due to creation of a reduced flow passage.

The reason why Experimental example (c) exhibits the best flow rate efficiency with respect to flow rate compared to other Experimental examples is that a vortex-generating area is reduced and thus the drive motor 300 creates a narrow flow passage together with the intake duct thus reducing a low pressure region of the flow passage.

In Experimental example (c), the diameter line (D2) of the drive motor 300 is about 80% of the minimum intake diameter line (D1) of the intake duct 110, and a distance between the bottom of the drive motor 300 and the outer end of the intake duct 110 is about 25% of the minimum intake diameter line (D1). Accordingly, it is preferable that the half (35 mm) of the axial length of the drive motor 300 is inserted into the impeller 100 through the intake duct 110.

More specifically, since the minimum intake diameter line (D1) is 144 mm and the diameter line (D2) of the drive motor 300 is 116 mm, the diameter line (D2) of the drive motor 300 is about 80% of the minimum intake diameter line (D1). Consequently, flow rate can be increased through the area of the remaining about 20% during intake of air, as illustrated in FIG. 6A and FIG. 6B.

However, since the diameter line (D2) of the drive motor 300 and the minimum intake diameter line (D1) may vary depending on a size of the double suction blower, it is preferable that the diameter line (D1) of the drive motor 300 is within the range of 75% to 85% of the minimum intake diameter line (D1) of the intake duct 110.

As mentioned above, the length (35 mm) of the part of the drive motor 300 which is partially inserted into the impeller 100 through the intake duct 110 is about 25% of the minimum intake diameter line (D1). At this point, since the length of the part of the drive motor 300 and the minimum intake diameter line (D1) may vary depending on a size of the double suction blower, it is preferable that the length of the part of the drive motor 300 is within the range of 20% to 30% of the minimum intake diameter line (D1).

As described above, by partially inserting the drive motor 300 into the impeller 100, the present invention intends to eliminate the phenomenon in which a flow rate of air introduced into the impeller 100 by the drive motor 300 is reduced in case of a double suction blower having the drive motor 300 installed at one side of the impeller 100. In other words, the present invention intends to provide the optimal installation position for the drive motor 300 which allows the flow rate of air to be maintained constant thanks to creation of a reduced flow passage in the impeller owing to the insertion of the drive motor 300.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 

1. An installation structure for a drive motor of a double suction blower, comprising: an impeller which is configured to axially draw in air at axially both sides thereof and to radially expel the drawn air and which is divided into two halves by a partition wall; a case accommodating the impeller, the case including air intake holes formed at both sides thereof to allow air to be introduced into the impeller at both sides of the impeller and including an outtake guide duct to guide the air radially expelled outside from the impeller; and a drive motor installed at one side of the impeller and coupled to the center of the partition wall to rotate the impeller, wherein the drive motor is disposed at a position in which the drive motor is partially inserted into the impeller from an outer end of the impeller.
 2. The installation structure for a drive motor of a double suction blower according to claim 1, wherein the impeller includes intake ducts axially at both sides thereof to allow air to be drawn in the impeller by the drive motor, the intake duct being flared outward.
 3. The installation structure for a drive motor of a double suction blower according to claim 2, wherein the drive motor is disposed at a position in which the drive motor is partially inserted into a minimum intake diameter line of the intake ducts.
 4. The installation structure for a drive motor of a double suction blower according to claim 3, wherein the drive motor includes a housing configured to have cylindrical shape, and a diameter line of the housing is within a range of 75% to 85% of the minimum intake diameter line of the intake duct.
 5. The installation structure for a drive motor of a double suction blower according to claim 4, wherein the drive motor is disposed in the impeller through the minimum intake diameter line such that an end of the drive motor is positioned at a distance from an outer end of the impeller, the distance being within the range of 20% to 30% of the minimum intake diameter line. 